SOME REFLEXIONS AND QUESTIONS ABOUT APERIODIC CRYSTALS

Abstract
I enjoyed tremendously this workshop ! Denis Gratias and I thank cordially all the participants to have made it. I learned a lot ; mainly about experimental facts and methods. How clever are experimentalists ! I sympathized very much with the theorists : it is amusing to play with models ! I was fascinated by the works of mathematicians here. Thanks to the excellent logistic of Les Houches "Centre de Physique", I could be very relaxed from the responsabilities I had ; so I had a lot of time for thinking and discussing. As a result, many questions arise that I cannot answer so I will share them with you.